The International Conference on Information Processing in Medical Imaging is a forum for researchers involved in the following aspects of biomedical imaging: physical, biological and statistical modeling;image formation and reconstruction;computational image analysis;visualization;and image quality assessment. The 2009 meeting will be held at the College of William &Mary in Williamsburg, VA on July 5-10. Historically, IPMI conferences have had a major impact on the medical imaging community including the introduction of seminal papers and helping students and junior faculty mature into leaders in the field. IPMI conferences are week-long, Monday through Friday, and are held in rural settings like small college towns or conference centers. Venues are selected for their ability to provide an environment that minimizes costs and distractions while promoting collegiality and scholarly discussion. A main goal is to bring together leaders in the research community with students and junior faculty for informal, detailed and intensive scientific discussions on fundamental aspects of image science and information processing. Sessions are always single track, never in parallel. All participants use the same facilities for lodging and food, usually provided through the hosting college. Approximately 28 oral presentations (7 sessions) and 24 poster presentations (2 sessions), selected based on peer-reviewed 12 page submitted manuscripts, are made during the five-day conference. Each oral presentation is allotted 60 minutes - 20 minutes for presentation and nominally 40 minutes for discussion. Each attendee is assigned to at least one focus group that studies 4-6 papers from the conference proceedings, which are distributed at the onset of the conference. This format encourages participation in discussions by all attendees, regardless of age or status, and promotes a deeper analysis of the fundamental issues raised by the presentations. Scientific discussion is never time limited. Virtually all IPMI participants will attest that there is no better forum for productive scientific exchange on medical imaging. Participants who are not presenting must apply to attend IPMI. An application form is submitted listing the applicant's credentials and list of recent publications. To ensure an intimate atmosphere conducive to discussion, total attendance is limited to approximately 130 people. Participation from junior faculty, postdoctoral fellows, and advanced graduate students typically comprise approximately 30-40% of the audience and more than 50% of the presentations. Women, minorities, and persons with disabilities are actively encouraged to attend and participate in the Call for Papers, advertisements, and targeted personal contacts. Where possible, discounted or waived registration fees are offered to younger attendees and participants from underrepresented groups.